The Season 5 Premier was filled with a number of major twists, both in the course of the war, and with the key character plots running in the background.
Now, as the title of this volume implies, the war has crossed some undefined line that marks a point of no return. The historical energy that eventually crushed Nazi Germany and Imperial Japan exerts
its unremitting gravity, and it remains to be seen if the Axis can recover any semblance of the power they once wielded.

In the East, a powerful new Soviet offensive sees German attention, and their available reserves, move to Armeegruppe Center. Manstein must relinquish Steiner’s
vaunted SS Korps, and he can only hope he has seen the last of the Soviet offensive he was contending with in earlier volumes. In the West, General Marshall has wrested control of the strategy and
forced it into Southern France, where the Allies mount a daring, if hasty drive into the French Riviera instead on pursuing their Italian Campaign. That was smart, and it sends both sides into a
whirlwind campaign in the south of France.

Patton takes Bayonne and drives north with little difficulty to Bordeaux. Clark and Bradley hold the center, and in the east, Montgomery seizes Toulon, Marseilles, and
drives into the Rhone River Valley. But now the front stretches 350 miles across France, and the Allies find they have barely enough divisions in theater to cover that turf, let alone generate enough
concentrated power to go on the attack. The Germans have also strained to send every available division to Southern France, from Italy, Germans and the Balkans. Flushed with their initial advance,
Eisenhower and company now realize they need more power before they can attack, for the Germans still have another 20 divisions along the coast in the 15th and 7th Armies, and have already begun
counter-punching with Himmler’s new SS divisions, a few veteran Panzer units, and the elite Brandenburgers.

So have no fear, in spite of the most dramatic and unexpected event of Prime Meridian, the alternate history war we have been following since Volume 9 (Altered States)
will continue. That event was, of course, Tyrenkov’s stunning betrayal on his mission to get Volkov and Orlov. He finds them easily enough, but has decided to rule in hell rather than to serve
in heaven, a decision that has deep repercussions that have yet to fully manifest.

The cover of Event Horizon shows us that event clearly enough--the burning destruction of the railway inn at Ilanskiy. Tyrenkov has made his choice, secured allies in Volkov and Orlov, and now he has burned his bridges, doing so as much to prevent Fedorov and Karpov from interfering as anything else. Karpov’s ruthlessly efficient Chief of Intelligence and Security now has powerful allies in 1908, and his mischief gets underway here in Event Horizon.
Now Fedorov and the Siberian Karpov discover what has happened, and begin to wrestle with the consequences. The world around them has already begun to change, at least from their vantage point aboard
the airship Tunguska, and with Ilanskiy destroyed, how will they get back to 1908 to try and stop Tyrenkov? That is a tall order, but the unique qualities of Tunguska, both the airship
and that dreadful place in the wilds of Siberia, give our heroes a chance.

Yet like a good chess player, Tyrenkov has already looked several moves ahead in this deadly game. He has set plots in motion in 1943 to get to Karpov and Fedorov before
they can get to him. Beyond that, he has realized that Karpov and his battlecruiser are scheduled to appear in the Pacific in just ten days, and he knows that the Siberian is going to make a theatric
landing at Vladiviostok. So that is where our trio of traitors are headed, but there will be surprises ahead for them as well.

Meanwhile, the war continues, and with twelve chapters here devoted to the Pacific. As the Japanese strongly reinforce the Solomons with some of their best divisions from
China, the US now contemplates their strategic choices. They have now gone over the Event Horizon in terms of carrier power in the Pacific, able to meet and best the Japanese in head on duels. The
next major clash sees Yamamoto striking at the one chink in his armor, Milne Bay,which is still held by the Australians. Halsey tries to get reinforcements there while Yamamoto lands a full
divisions to close that door into New Guinea.

Then we get another course change as Nimitz asks the Joint Chiefs for a directive to go into the Gilbert and Marshall Islands, which means he must first lock horns with
MacArthur over strategy. Where will the major emphasis be? Mac wants to pursue his campaign with the army through New Guinea, while Nimitz wants to begin the island hopping strategy that truly won
the war by delivering key bomber bases to the US. The result sets the campaign in motion, from the strategic moves, to the operational maneuvers, the focus gets tighter and tighter until we finally
zoom in to the tactical level, right down to one man vs another in the fighting that results.

So all three fronts get time here, six chapters on the East Front, three on the West Front and twelve in the Pacific. The remaining fifteen chapters
all go to the major characters, struggling with issues that will eventually decide which time line prevails and becomes the new Prime Meridian. Some of those go to the odyssey of the Kaiser Wilhelm,
which soon becomes a deadly new raider on the high seas of WWI. And yes, for the first time in a good long while, we walk the deck of Kirov again in this volume. While the Siberian is off aboard Tunguska,
his younger brother-self gets restless, and takes Kirov and Kazan south into the Pacific. There’s lots more action ahead in that move, because Admiral Kita has decided to intervene to prevent the American drive into the Marshalls. Get ready for fireworks, as the modern ships are sure to face off again soon.